rhone



(No Model.) 2 Sheets-#Sheet 2.

C. E. RHONE. DENTAL ENGINE.

No. 492,433. 4"lebmmted Feb. 28, 1893.

y WMZ@ T s Nonms PETERS cn. pHoro-umu., wAsmNnroN D c UNrrnnv STATES PATENT OFFICE.

CHARLES E. RHONE, OE BELLEFONTE, PENNSYLVANIA.

DENTAL ENGINE.

STECIFICATION forming part of Letters Patent No. 492,433, dated February 28, 1893..

Application filed October 15, 1892. Serial No. 449,017. (No model.)

To a/ZZ whom it may concern:

Be it known that I, CHARLES E. RHONE, a citizen of the United. States of America, residing at Bellefonte, in the county of Centre, in the State of Pennsylvania, have invented a new and Yuseful Improvement in Dental Engines, of which the following is a specification.

This invention relates to dental engines which when in use are usually attached tothe walland operated by a motor, and in which the engine arm is capable of universal adjustment in any direction and free to be moved at the will of the operator and adapted to maintain itself in its adjusted position Without the manipulation of a set screw or other locking device on the part of the operator.

The object of this invention is to secure in an adjustable dental engine arm the combined properties in a high degree of stability of position, elasticity of adjustment, and durability' of the connection.

Figure 1 of the accompanying drawings represents a perspective view of this improved dental engine arm omitting the motor and the tension device for the driving cord. Fig. 2 is a horizontal section of the supporting bracket, a portion of the engine arm pivoted thereto, and the automatic clamping device for holding said arm in adjusted position on said bracket. Fig. 3 represents a transverse section on line 3-3 of Fig. 2. Fig. 4 represents perspective views of the clamping plate and one of the bow springs constituting parts of the clamp for connecting the engine arm and bracket.

The same reference numbers indicate the same parts in the dierent figures.

The wall plate 10 is designed to be attached to the wall in any desired position adjacent to the dental chair or it may constitute an upright standard attached to the floor adjacent to said chair. A fixed plate 11 provided with ears 12 and 13 near its ends is attached to said Wall plate. A swiveled bracket 30 is hinged between the ears 12 and 13 by means of pivots, as 3l, which may be in the form of screws passing throughsaid ears and entering sockets in the vertical rear arm 33 of said bracket. The front arm 34 of said bracket is preferably arc-shaped and provided with a slot 35 preferably arc-shaped. A lug 36 preferably depends from the lower bar of said bracket carrying pulleys 37 and 3S journaled on studs on said lug.

An engine arm 40 is pivoted to the rear arm 33 of the swiveled bracket 30. This engine arm is preferably constructed in three sections, a rear section 41, pivoted as aforesaid, an outer tubular section 5l attached to or formed integral with the outer end of the seetion 4l, andan inner tubular section 61 sliding within'the outer section 5l. The rear section 41 is provided on its outer end on its outer face with an angular transverse recess 43 and on its inner face with a circular .recess 44 surrounded by a rim or flange 45. Astud hole 46 is disposed near the recess 43. A larger stud hole 47 connects the two recesses 43 and 44, forming a shoulder 48 at the base of the circular recess.

A clamping plate 70 provided with. a central stud 71 and with a smaller stud 72, is disposed on one face of the engine arm opposite the recess 43 therein. The small locking stud 72 enters the stud hole 46 of said arm and locks the plate in position thereon, while the larger stud 7l extends through the central stud hole and projects on the opposite face of said arm, said larger stud being screwthreaded at its outer end. This clamping plate is provided with a recess 73 on its inner faceopposite the recess 43 of the engine arm. A thumb nut 8() having a circular recess on its inner face corresponding with the circular recess of the engine arm, is adapted to engage the screw-threaded end of thecentral stud 71. A spiral spring S5 is disposed around said stud in said circular recesses, bearing at its inner end against the shoulder 48 of the engine arm and its outer end against. saidl nut.

The arm 34 of the bracket 30 extends thron gh the transverse recess in the engine arm and two bow springs 90 and 91 are disposed on opposite sides of said bracket arm, said springs these sp rings are provided with frictional contact faces and bear against the curved arm 34 of the bracket 30. These springs serve to impart sufficient friction to overcome the Weight of the engine arm. When the latter is swung lin the desired position, it will remain there without a locking device; yet owing to the springs on opposite sides it has an elastic adjustment and is sufficiently free to be moved under pressure of the hand of the operator into the desired position.

when required by the thumb nut 80, and by the auxiliary tension spring 85 around the;

. nut and the engine arm, substantially as set stud 71.

In assembling the parts, after the enginel arm 41 is pivoted to the arm 33 of the bracket 30, and the slotted arm 34 of this bracketg rests in the transverse recess 43 of said arm,

the bow-spring 91 is placed between said slotted arm 34 and theinner face ,of said re cess, its hole being adjusted opposite the hole 47 in said arm. The other bow-spring 90 is then placed on the stud 71 of the clampingl plate 70 and disposed in the recess of said plate. then passed through the slot of .the arm 34,

through the hole in the spring 91and through The spiral spring 85 is then passed over said stud 71 downinto The the hole 47 lin the arm 41.

the circular recess 44 of the arm 41. thumb nut l8,0 is then screwed onto the stud 7l and theannular recess at the inner end thereof closes down over the outer end of the spring 85.

In the use of adentalengi-ue provided with" this improved connection for the pivoted engine arm, lwhen the latter arm is adjusted, it will yield readily tothe pressure of the hand of the operator for that purpose and yet the tension of the springs is such -as to hold it The ,ten-` sion ot' the springs referred to is regulatedA The stud 71 of said clamping plate is` on said stud for adjusting the tensionof said spring. Y v

2. The combination of a bracket having a slotted arm, a pivoted engine arm movable on said slotted arm, a clamping plate provided with a stud passing through said slotted arm, a spring between said engine arm and said slotted arm, a spring between said clamping plate and said slotted arm, a thumb-nut on said stud, and a spring between the thumbforth.

3. The'combination of a bracket having a slotted arm., a `pivoted engine arm movable on slotted arm, Aa pivoted `arm ,movable on said slotted yarm and provided with a transverse recess and with yastnd hole on-onesideof said recess, .a clampingplate provided with a central stud passing through saidar-m, .and with a lookin g stud entering saidstud-hole, springs on opposite sides of said arm, engaged `bysaid clamping plate and by;said.armand anut on said central stud.

5. The .combination of a slotted member, a pivoted member movable thereon, and provided With a transverse recess in one faceand with a circular recess Aon the opposite face, a clamping plate provided with a stud passing through said arm and recesses, springs in said recesses and bearing against said slotted arm, a :nut on said stud `pro-vided with a circular recess at its Ainner end, and a spiral spring disposed around said stud in said circular recesses.

CHARLES E. RHONE.

Witnesses:

D. L. KELLER, J. W. RHONE. 

